Tribological Investigation of Grease Used in Automotive Constant-Velocity Joints

摘要

High performance greases with separate additive formulations for low friction and wearhave been developed specifically for constant-velocity (CV) joints. In this paper, CV jointgrease performance was investigated using a versatile pin-on-disk tribometer. 4121-H modifiedsteel disks were procured under the same conditions as an actual CV joint housing and weretested against 52100 steel pins, simulating the roller. To evaluate the effectiveness of CV jointgrease, sliding friction and wear under dry and two different types of greases were measured.Experiments under different contacting conditions, such as normal load, contact area, and slidingvelocity, were also performed to investigate the friction and wear dependencies. To quantify thesurface changes and wear occurring with tribotesting, pin wear lengths and surface profiles of thedisk wear tracks were measured. Finally, scanning electron microscopy images of the weartracks were obtained to investigate the wear mechanisms. It is clear that CV joint grease offerssignificant improvement of friction reduction and shows stable and convergence tendenciesunder various contacting conditions.